Starting back out again (I'm new!)

[CG]

Hi, I'm planning on getting started back into the whole PIC thing.

Few years ago, I was playing with 16F84 and 16F628 in a mech. class. I used Microcode Studio and with some Melabs programmer(forgot which). Unfortunately, I forgot everything.

I was browsing around the other day, and found a few JDM programmers that are cheap(programmers used to be upwards of 100 bucks), so I decided to try playing with pics again. Right now, I have on order 2x 16F877 (they're not samples from microchip), and various crystals(still need ceramic caps).

Anyways, I'm starting out completely clueless about pics again, and I'm stuck with a couple problems:

which software should I use? looking online, I see people using winpic800, ic-prog or epic. which would be the best for my 16f877?

also, I was planning out the blinking led project and I calculated that i need ~130ohm resistors, but websites online say that you need 470-600ohm resistors.
Why?
I calculated as follows LED amp = .025A, Vsource = 5V Vtarget = 1.7V.
So V = IR, we get:

.025*130 = 3.3V
5V - 3.3V = 1.7V

Did i do something wrong?

 

[aj9999]

Im new also , I use a 16f877a or 18f4520 and MPLAB with the C18 compiler which i find easy to use. I would recommend buying a cheap development board , i use the PICDEM2+ with an ICD3. I believe it is easier to learn to program without having to worry about hardware issues that a homemade board could cause.

As for the resistor value i think your mistake is the current of 25mA. You didnt mention a specific LED type but it is common for LED's to run ~10ma , so if you take the given values of 5v / 470 ohm you get ~10mA

good luck

 

[Tahmid]

Hi,

If you're starting over again, I recommend you use mikroC or mikroBASIC compiler.

http://www.mikroe.com/en/compilers/mikroc/pro/pic/

[url]https://www.mikroe.com/en/compilers/mikrobasic/pro/pic/[/url]

If you plan to be using PICs for a long enough time, you'd be better getting a PICKit2 (or PICKit3, although I don't know much about this).
If you want, you could get the EasyPIC5 or EasyPIC6 from mikroElektronika or you could just use a breadboard or verroboard.

For resistor and blinking LED:

Consider LED current = 10mA = 0.01A, for red LED, 1.7v, for green 2.3v, for blue 3.5v, etc.
I assume you're using a red LED.
So, V = 5v - 1.7v = 3.3v
I = V/R = 3.3/0.01 = 330R

For common general purpose low power LEDs, you should allow currents of about 10mA, which should be plenty.

Hope this helped.
Tahmid.